This just happened to me as well. I had taken pictures of several sims with no problems and suddenly, it freezes. Exactly the same issues as the OP. I could click the close buttons, the camera buttons, the filters, everything, but nothing happened. Also, the hot keys to open the cheat windows, exit the camera, take photos, nothing would work. Tried several tricks, like switching between programs to see if I could get it to shock back to life. Finally gave up and shut it down using the task manager. Recreated this same problem 6 different times, with 3 different single sims. I have no mods, all packs. This problem was done with the cheap digital camera and also the camera on my sim's phone. I've been saving right before taking the photos, but it's still frustrating.
